1. Field of the Invention
This invention relates to a method for treating a body of a polluted porous medium, more particularly to a method for treating a body of a polluted porous medium using nanoparticles.
2. Description of the Related Art
In recent years, nanotechnology has a great impact on the fields of biotechnology, energy source, information, microelectromechanics, and environmental engineering due to the specific properties of nanoscale particles. Specifically, it is found that when the dimensions of a particulate particle are reduced to nano-scale, e.g., 1 to 100 nm, the physicochemical properties thereof, such as specific surface area, optical property, electrical property, magnetic property, configuration, and reactivity, are markedly changed, and reactivity thereof is greatly improved.
For example, nanotechnology has been applied to environmental engineering including pollution prevention, treatment, and remediation. Research has shown that iron nanoparticles having high reactivity and large surface area can be used to remedy polluted subsurface environment, e.g., soil and ground water. Compared with iron particles having larger dimensions, iron nanoparticles reported have a superior effect on the treatment of chlorinated organic solvents, organochlorine pesticides, heavy metals, and radionuclides. In addition, environmental remediation of contaminated sites using the iron nanoparticles has been developed to a scale of in situ field test. For example, a suspension including the iron nanoparticles is injected into ground water under a gravity-fed or pressurized condition, and is transported by the flow of ground water through a polluted porous medium, such as contaminated soil or polluted ground water, so as to degrade the contaminants into non-toxic compounds.
However, the transporting rate of the suspension including the nanoscale iron particles by the flow of the ground water is relatively slow such that the efficiency for environmental remediation is limited.